The track element is provided on the main wing, preferably on an upper surface of a structure element of the main wing, and extends in a chordwise direction of the wing. The structure element may be arranged under the skin of the main wing, but may also be arranged outside of said skin or extending through said skin. The track element has at least a first support surface and at least a first track side wall extending transverse to the first support surface. The first support surface preferably extends in parallel to the upper surface of the structure element of the main wing.
The actuator device is provided on the main wing and configured for moving the high lift element relative to the main wing in order to adjust the geometry of the aircraft wing, and thus to adjust the resulting lift of the aircraft wing. The actuator device may be formed as e.g. a rotary drive.
The drive rod has an element end which is, preferably in a pivotal manner, connected to the high lift element, and an actuator end that is, preferably in a pivotal manner, connected to the actuator device. In such a manner the drive rod connects the actuator device to the high lift element and transfers movement of the actuator device to the high lift element.
The carriage device is, preferably in a pivotal manner, connected to the high lift element and has an engagement portion that engages the track element in such a manner that a linear movement of the engagement portion along the track element is permitted. This linear movement is guided by the drive rod, or by the track element during engagement of the engagement portion of the carriage device to the track element.
In the prior art, the engagement portion of the carriage device comprises one or more rollers, usually four rollers that are spaced from each other in-line and in parallel, which engage the first support surface of the track element in order to be moved along the track element supported by the first support surface.
Undesirable and dangerous situations may arise when during flight, take off, or landing of an aircraft one of the connecting systems fail, e.g. by fracture of the drive rod, the actuator device, or one of the hinges connecting the drive rod to the actuator device or to the high lift element. In these cases one of the load paths from the high lift element to the main wing is interrupted, so that the high lift element skews with respect to the main wing and with respect to possible further high lift elements, which could interfere with the operation of the high lift element.
Therefore, there are aircraft wings known in the art that are configured in a fail-safe manner such that, when one of the connecting systems connecting the high lift element to the main wing fails, the high lift element is still kept in its position relative to the main wing and to possible further high lift elements and is not skewed with respect to the main wing by more than a certain uncritical tolerance.
One option known in the art to prevent the interfered operation of the high lift element mentioned above after failure of one of the connecting systems is to interconnect two adjacent high lift elements by means of an interconnecting device, so that when one of the connecting systems fails the high lift element is still held in place by the remaining connecting system and the interconnecting device connected to the adjacent high lift element. However, such interconnecting device can only be employed between high lift elements that are configured to operate in common, i.e. move simultaneously, as it is the case for high lift systems employing a central transmission shaft to which each of the high lift elements are coupled for common movement.
However, in an increasing number of aircraft models it is desired to configure the high lift systems in such a manner that each high lift element may be controlled and moved individually without a central transmission shaft moving all high lift elements commonly, but instead with separate transmission shafts and actuator devices each of which are responsible for movement of a single high lift element independent from the other high lift elements. For such independently actuated high lift elements it is known in the art to provide a so called fail safe connecting system connecting the high lift element to the main wing. Such fail safe connecting systems include a safety or backup connection, such as a safety rod, connecting the high lift element to the main wing in addition to the usual drive rod, so that when e.g. the drive rod fails, the high lift element is still held in position by the safety connection.
However, such fail safe connecting systems are disadvantageous, because the safety connection consumes additional space on the main wing and on the high lift element, and carries additional weight, which is generally desired to be reduced in aircraft construction.
Therefore, the object of the present embodiments described herein is to provide an aircraft wing that is configured in such a manner that when the connecting system for connecting the high lift element to the main wing fails, the high lift element can still be held in a possibly unskewed position, and wherein at the same time, possibly little additional room is consumed and possibly little additional weight is introduced in the aircraft wing.
This object is achieved by the engagement portion comprising a bearing including a slide bearing, the bearing having a first bearing surface and a first bearing side wall extending transverse to the first bearing surface, wherein the first bearing surface is supported by and adapted to move along the corresponding first support surface of the track element. The bearing and the track element engage in such a manner that when the bearing or slide bearing is aligned with the track element the first track side wall and the first bearing side wall are spaced apart from each other so that the linear movement of the carriage device along the track element is permitted, and when the bearing or slide bearing is skewed with respect to the track element the first bearing side wall contacts the first track side wall so that the bearing or slide bearing is locked against the track element and movement of the carriage device along the track element is inhibited.
In other words, when the bearing and the track element are engaged, the bearing can be moved relative to the track element between an aligned position taken during normal operation of the high lift element, where the bearing is aligned with respect to the direction of extension of the track element, and a skewed position taken after failure of one of the connecting systems, where the bearing is skewed with respect to the direction of extension of the track element.
When the bearing is in the aligned position, the first track side wall and the first bearing side wall are spaced from each other by a, preferably constant, gap, so that the linear movement of the carriage device, i.e. the engagement portion, along the track element is possible. The lower limit of the size of the gap is defined by the precondition that in the aligned position of the bearing relative movement between the bearing and the track element in the direction along the track element is possible. The upper limit of the size of the gap is defined by the length of the diagonal or longest diameter of the bearing. The preferred size of the gap is located between the upper and lower limit but considerably closer to the lower limit, since it is desired to lock the high lift element in a skewed position with a possibly small skew angle.
In the skewed position of the bearing, the first bearing side wall contacts the first track side wall so that the bearing is locked against the track element and further linear movement of the carriage device along the track element as well as further skewing is inhibited. The locking of the bearing against the track element can mean that the bearing is fixed in its position and may be moved neither such that the skew angle is increased, nor such that the skew angle is decreased. It can also mean that merely no further skewing, i.e. increasing of the skew angle is possible, but a movement in order to decrease the skew angle would indeed be possible.
By means of the bearing that can be moved between an aligned position and a skewed position as described herein, a very simple and effective way of locking a high lift element in a fixed position after failing of one of the connecting systems, e.g. by rupturing of one of the drive rods, is provided. After rupture of a drive rod, the associated high lift element is skewed due to the aerodynamic loads on the high lift element and the missing or interrupted load path represented by the ruptured drive rod. The skewing of the high lift element causes a skewing of the attached bearing with respect to the track element of the connecting system of the ruptured drive rod. When the slide bearing is skewed by a certain angle with respect to the track element, the first bearing side wall contacts and locks against the first track side wall so that no further movement of the bearing along the track element, and thus no further skew angle is possible. The high lift element is held in its stable position until landing of the aircraft, where the broken connecting system can be repaired. No relevant further weight is introduced and no relevant further space is required for such a connecting system as described herein.
In a simple embodiment, all or just a part of the rollers of the carriage device of an aircraft wing known in the art are replaced by slide bearings.
According to a preferred embodiment, the track element comprises a second track side wall, and the bearing comprises a second bearing side wall. The bearing or slide bearing and the track element engage in analogous manner as described before in connection with the first track side wall and the first bearing side wall. When the bearing or slide bearing is aligned with the track element, the second track side wall and the second bearing side wall are spaced from each other so that the linear movement of the carriage device along the track element is permitted. When the bearing or slide bearing skewed is with respect to the track element, the second bearing side wall contacts the second track side wall so that the bearing or slide bearing is locked against the track element, and movement of the carriage device along the track element is inhibited.
By introducing the second track side wall and the second bearing side wall, a more effective locking of the bearing against the track element can be established, wherein it is preferred that the first track side wall and the second track side wall are provided on opposite sides of the track element, and the first bearing side wall and the second bearing side wall are provided on opposite sides of the slide bearing.
In particular, it is preferred that the bearing is formed as the slide bearing, and the first bearing surface is formed as a first slide surface adapted to slide along the corresponding first support surface of the track element. In other words, the bearing has no other components but the slide bearing. Therefore, the first bearing surface must be formed as a first slide surface.
In particular, it is preferred that the first track side wall and the second track side wall are arranged in a track recess of the track element in an opposite manner such that their surfaces point to one another. The first bearing side wall and the second bearing side wall are arranged on a bearing projection of the slide bearing in an opposite manner such that their surfaces point away from one another. It is further preferred that the first support surface is arranged on the bottom side of the track recess, and the first slide surface is arranged on the front side of the bearing projection.
In such a manner, the slide bearing can effectively be guided on the track element and, when skewed, effectively be locked against the track element.
In an alternative embodiment, the first track side wall and the second track side wall are arranged on a track projection of the track element in an opposite manner such that their surfaces point away from one another. The first bearing side wall and the second bearing side wall are arranged in a bearing recess of the slide bearing in an opposite manner such that their surfaces point to one another. It is further preferred that the first support surface is arranged on the front side of the track projection, and the first slide surface is arranged on the bottom side of the bearing recess.
In such a manner, the slide bearing can effectively be guided along the track element and, when skewed, effectively be locked against the track element.
Alternatively, it is preferred that the first support surface is arranged on the track element adjacent the track projection on a first side of the track projection. A second support surface is arranged on the track element adjacent the track projection on a second side of the track projection opposite the first side. The bearing recess is defined between a first bearing projection portion and a second bearing projection portion. The first slide surface is arranged on the front side of the first bearing projection portion. A second slide surface is arranged on the front side of the second bearing projection portion. The second slide surface is adapted to slide along the corresponding second support surface. In such a manner the slide bearing can slide along the track element in a very stable manner and at the same time, when skewed, be locked against the track element most effectively.
According to a preferred embodiment the bearing comprises the slide bearing for transferring loads in the plane in which the aircraft wing mainly extends, and a roller arrangement for transferring loads transverse to the plane in which the aircraft wing mainly extends. The roller arrangement has at least a first roller element, wherein the peripheral surface of the first roller element comprises the first bearing surface. The slide bearing comprises a first slide element having the first bearing side wall, and a second slide element having the second bearing side wall. The first slide element and the second slide element are preferably formed as a friction pad, and are arranged in an opposite manner such that the first bearing side wall and the second bearing side wall point to one another.
In particular, it is preferred that the track element has a T-shaped cross section including a lower portion and an upper portion. The lower portion is connected to the main wing and extends away from the upper surface of the structure element of the main wing. The upper portion extends in parallel to the upper surface of the structure element and has a top surface pointing away from the upper surface of the structure element, a bottom surface pointing to the upper surface of the structure element, as well as first and second side surfaces pointing away from each other and connecting the top surface to the bottom surface.
The top surface comprises the first support surface. The roller arrangement has a second roller element, the peripheral surface of which comprises a second bearing surface, and a third roller element the peripheral surface of which comprises a third bearing surface. The bottom surface comprises a second support surface on a first side of the lower portion and a third support surface on a second side of the lower portion opposite the first side.
The second bearing surface is supported by and adapted to move along the corresponding second support surface, and the third bearing surface is supported by and adapted to move along the corresponding third support surface. The first side surface comprises the first track side wall, and the second side surface comprises the second track side wall.
Further, it is preferred that the roller arrangement comprises a fourth roller element that is arranged in line with the first roller element, a fifth roller element that is arranged in line with the second roller element, and a sixth roller element that is arranged in line with the third roller element. The lines extend in parallel to the track element. First and second slide elements are arranged, preferably centrally, between the first, second, and third roller elements on the one hand, and the fourth, fifth, and sixth roller elements on the other hand.
By a an aircraft wing having a bearing and a track element formed in accordance with the afore-described embodiments, a particularly effective guiding on the one hand and blocking on the other hand can be established.
According to a preferred embodiment, a first ratchet mechanism is provided between the first track side wall and the first bearing side wall. The ratchet mechanism comprises a first ratchet component mounted to the first track side wall and a second ratchet component mounted to the first bearing side wall. The first ratchet component and the second ratchet component are adapted to engage in a direction of engagement when the first bearing side wall contacts the first track side wall, such that upon engagement a relative movement of first and second ratchet component opposite the direction of engagement is inhibited.
In particular, it is preferred that a second ratchet mechanism is provided between the second track side wall and the second bearing side wall. The second ratchet mechanism comprises a third ratchet component mounted to the second track side wall and a fourth ratchet component mounted to the second bearing side wall. The third ratchet component and the fourth ratchet component are adapted to engage in a direction of engagement, when the second bearing side wall contacts the second track side wall, such that upon engagement a relative movement of third and fourth ratchet component opposite the direction of engagement is inhibited.
By the first and/or the second ratchet mechanism, the slide bearing, and thus, the high lift element, can be locked in the skewed position, where the first track side wall contacts the first bearing side wall and/or the second track side wall contacts the second bearing side wall, also with respect to a backwards direction out of the skewed position in the aligned position, i.e. opposite the direction of engagement of the associated first and second or third and fourth ratchet components. In this, it can be ensured that when one of the connecting systems fails during flight and the high lift element is skewed and then locked in the skewed position by the first bearing side wall contacting and engaging the first track side wall and the second bearing side wall contacting and engaging the second track side wall, the high lift element, which during flight is under permanent aerodynamic loading, may not move backwards, i.e. out of the skewed position into the aligned position or even vibrating between the skewed and the aligned position, which could cause further damage to the high lift element and to the entire wing.
According to a further embodiment, at least one of the first and second track side wall and the first and second bearing side wall is provided with an anti-slip surface. By such an anti-slip surface of the first or second track side wall or the first or second bearing side wall, when the first bearing side wall contacts the first track side wall and/or the second bearing side wall contacts the second track side wall, the slide bearing is effectively locked in the skewed position by a friction force between the first bearing side wall and first track side wall and/or second bearing side wall and second track side wall. Such anti-slip surface may be established in various ways, e.g. by a certain surface roughness or by an anti-slip coating.
A further aspect of the embodiment relates to an aircraft comprising a wing according to any of the afore-described embodiments. All features and advantages described before in connection with the wing in the same way apply to the aircraft.